rhm, on 2014-June-12, 02:30, said:
This is only true if you never stop below game.
It makes little sense when grouping weak and invitational hands.
Besides, I have seen opponents interfere over your weak hands. If your LHO is going to bid 2♠ the number of sequences available to you are exactly the same, whether you respond 2♦ or 1NT previously.
I prefer 2/1 but it is a tradeoff. The arguments are complex and can not be simplified.
When answering someone that does not understand 2/1 it is not only possible but also necessary to simplify the arguments. I post quite a lot in N/B and am used to doing this.
It is true that interference complicates matters and that the opponents are likely to bid over weak hands. That is one reason my own choice is to group invitational and GF hands together and use immediate change of suit responses as natural and weak. But that has its own issues and is not particularly relevant to the OP.
rhm, on 2014-June-12, 02:41, said:
I like to play 1♠ - 2m as GF and 1♠ - 2♥ as INV but non-forcing..
This makes more sense since 1
♠ - 2
♥ now holds fewer hand types than 1
♠ - 2m whereas in the system we were discussing it held more. You could also play all of the 2 level response to 1
♠ as natural and invitational, grouping the weak and GF hands together in 1NT. There are many workable possibilities here.
rhm, on 2014-June-12, 02:41, said:
What I find strange is, that the whole debate centers around the issue whether all two over one sequences should be game forcing or not.
There are a few structures around that do this and I think straube has used one of these for example. I quite like keeping the 2/1 responses to 1
♠ of the same type because it helps with the homogeneity of the 1NT response. A classic mixed structure is for a 2
♣ response to be a GF relay with 2
♦ as INV+ with hearts. Then 1NT handles the rest. It happens less often with natural responses though.